St. Francis Dam

St. Francis Dam
View of the dam looking north, with water in its reservoir (c.1926)
Location	Los Angeles County, California, United States
Opening date	1926
Demolition date	1928
Dam and spillways
Height	195 feet (59 m)
Length	608 feet (185 m)
Impounds	Los Angeles Aqueduct San Francisquito Creek

The St. Francis Dam was a concrete gravity-arch dam, designed to create a reservoir as a storage point of the Los Angeles Aqueduct. It was located in San Francisquito Canyon of the Sierra Pelona Mountains, 40 miles (64 km) northwest of Los Angeles, California, near the present city of Santa Clarita.

The dam was built between 1924 and 1926 under the supervision of William Mulholland, chief engineer and general manager of the Los Angeles Department of Water and Power, then called the Bureau of Water Works and Supply. Two and one-half minutes before midnight on March 12, 1928, the dam failed, catastrophically, and the resulting flood killed more than 450 people. The collapse of the St. Francis Dam is one of the worst American civil engineering failures of the 20th century and remains the second-greatest loss of life in California's history, after the 1906 San Francisco Earthquake and fire. The disaster marked the end of Mulholland's career.

The approximate extent of the reservoir created by the dam

Planning and design

Mulholland, a self-taught civil engineer, had risen through the ranks of the Los Angeles Department of Water and Power, then called the Bureau of Water Works and Supply, and had quickly established himself as having a penchant for thriftiness, an enormous capacity for innovation, and the ability to complete difficult projects on-time and on-budget. These traits undoubtedly aided him in designing and building the Los Angeles Aqueduct in 1913, which at the time was the longest aqueduct in the world, bringing water 233 miles (380 km) from the Owens Valley to the city of Los Angeles.

The rapid growth of Los Angeles demanded a larger water supply, so a series of small reservoirs were built in the 1920s to provide the rapidly-expanding city with a water supply in the event of a drought or damage to the aqueduct, but the need for larger reservoirs was obvious.

In the process of designing and building the Los Angeles Aqueduct, Mulholland had considered sections of San Francisquito Canyon—beginning about 30 miles (50 km) north of Los Angeles—as a potential dam site in 1911. Conveniently, the Los Angeles Aqueduct ran along the canyon, and two generating stations in the same canyon used aqueduct water to provide power for Los Angeles. To Mulholland, the location appeared ideal—the reservoir would provide ample water for Los Angeles in the event of a drought or if the aqueduct was damaged by an earthquake or sabotage.

Construction and modification

In 1924, construction was quietly begun on the dam so as not to attract the attention of the farmers dependent on the water of San Francisquito Creek. Additionally, the Los Angeles Aqueduct was the target of frequent sabotage by angry farmers and landowners in the Owens Valley, and Mulholland was eager to avoid the kind of expensive and time-consuming repairs which plagued the Los Angeles Aqueduct. The dam was named the "St. Francis", an anglicized version of the name of the canyon in which it was built.

Immediately after construction had begun in 1924, Mulholland decided to raise the height of the dam 10 feet (3 m), increasing the capacity of the reservoir from 30,000 to 32,000 acre feet (39,000,000 m³) of water, and Mulholland made minor changes in the dam's design to accommodate the additional height.

In July 1925, when the dam was roughly half-completed, Mulholland added an additional 10 feet (3 m), bringing the dam's new height to 195 feet (59 m) and increasing the reservoir's capacity to more than 38,000 acre feet (47,000,000 m³) The dam's new height necessitated the construction of a "wing dike" along the top of the ridge of the western abutment to prevent water from spilling over the ridge.

Prelude to disaster

Throughout 1926 and 1927, several temperature and contraction cracks appeared in the dam as the reservoir filled. The cracks and leaks were inspected by Mulholland and his assistant, Harvey van Norman, and judged to be within expectation for a concrete dam the size of the St. Francis.

Through the closing months of 1927 to March 1928 the reservoir rose steadily, and uneventfully. On March 7, 1928 the reservoir had reached full capacity; Mulholland ordered that no more water be turned into the St. Francis.

Dam keeper Tony Harnischfeger discovered a new leak on the morning of March 12. The muddy color of the runoff could indicate that water was eroding the foundation of the dam, and Harnischfegar immediately alerted Mulholland. After inspecting the leak Mulholland and Van Norman determined that the muddy appearance of the water was not from the leak itself, but came from where the water contacted loose soil from a newly cut access road. Convinced that the leak was not a danger, Mulholland and Van Norman pronounced the dam safe.

Collapse and flood wave

Two and one-half minutes before midnight on March 12, 1928, the St. Francis Dam catastrophically failed.

Although there were no eyewitnesses to the dam's collapse itself, a motorcyclist named Ace Hopewell had ridden past the dam, by his approximation ten to fifteen minutes prior. In his testimony at the Coroner's Inquest, he stated he rode up the canyon and had passed both power house 2 and the dam without seeing anything which would cause concern. Approximately one mile (1609m) upstream of the dam he heard, above the sound of his motorcycle, what to him was much like "rocks rolling down the mountain." He stopped and checked the hillsides above him. The sound which he had heard earlier was behind him and he assumed this had possibly been a landslide as these were common to the area. It is believed that he was the last person to have seen the St. Francis Dam intact.

Dam keeper Harnischfeger and his family were the first casualties caught in the flood wave, also called dam break wave, which was at least 125 ft (38 m) high when it hit their cottage in San Francisquito Canyon, approximately 1/4 mile (400 m) downstream from the dam. Thirty minutes before the collapse a motorist passing by the dam also reported seeing lights in the canyon below the dam —the dam itself did not have lights—suggesting Harnischfeger may have been inspecting the dam immediately prior to its failure. The body of Leona Johnson, who lived with the Harnischfegers (and has been often and mistakenly reported to be Harnischfeger's wife) was found fully clothed and wedged between two blocks of concrete near the broken base of the dam. Neither Harnischfeger's body nor that of his six-year-old son, Coder, were ever found.

As the dam collapsed, twelve billion U.S. gallons (45 billion liters or 45 million m³) of water surged down San Francisquito Canyon in a dam break wave, demolishing the heavy concrete walls of Power Station Number Two (a hydroelectric power plant), and destroying everything else in its path. The flood traveled south down San Francisquito Canyon, flooding parts of present-day Valencia and Newhall. The deluge then turned west into the Santa Clara River bed, flooding the towns of Castaic Junction, Fillmore, and Bardsdale. The flood continued west through Santa Paula in Ventura County, emptying its victims and debris into the Pacific Ocean at Montalvo, 54 miles (87 km) from the reservoir and dam site. When it reached the ocean at 5:30 a.m., the flood was almost two miles (3 km) wide, traveling at a speed of 5 miles (8 km) per hour. Bodies of victims were recovered from the Pacific Ocean, some as far south as the Mexican border.

Telephone operators in Fillmore (notably Louise Gipe) and two motorcycle policemen in Santa Paula notified people in their homes of the danger, until the rising floodwaters forced their retreat.

The day after the disaster the front page of the Los Angeles Times ran four stories, including aerial photos of the obliterated dam, the city of Santa Paula after its wake and a partial list of the dead. It also set up a Times Flood Relief Fund, to receive donations from around the country. The Times also reported that Mullholland issued a statement saying, "I would not venture at this time to express a positive opinion as to the cause of the St. Francis Dam disaster." "Mr. Van Norman and I arrived at the scene of the break around 2:30am this morning. We saw at once that the dam was completely out and that the torrential flood of water from the reservoir had left an appalling record of death and destruction in the valley below." In the article, Mullholland stated that it appeared that there had been major movement in the hills forming the western buttress of the dam. However, he added that three eminent geologists, Robert T. Hill, C. F. Tolman and D. W. Murphy had been hired by the Board of Water and Power Commissioners to determine if this was the cause. It was noted that there were no tremors reported at seismograph stations and an earthquake could be ruled out as the cause of the break.

Huge concrete block from the west abutment of the dam about half a mile below the dam. The block is approximately 63 feet long, 30 feet high, and 54 feet wide. Note the dam wing wall in the distance. (March 17, 1928)

Looking across the canyon at the damsite today; the wing dike necessitated by the increased height of the dam is visible on the left, and the area of paleolandslide is visible on the far side of the canyon.

Remains of the "Tombstone" section of the dam in 2009. Note the partially-buried edges of the stair-stepped face of the dam.

Aftermath

The dam broke into several large pieces, some of which were carried almost a half mile (0.8 km) downstream, while the center section of the dam, nicknamed "The Tombstone", remained standing. (Cf. photo in ) Two months after the collapse, 18-year-old Lercy Parker fell to his death while climbing the ruins, and in the following months, the upright section was toppled with dynamite and the remaining blocks demolished with bulldozers and jackhammers to discourage sightseers and souvenir hunters from exploring the ruins. Although the west wing dike remained intact, it was used by Los Angeles firemen to gain experience of using explosives on building structures. The St. Francis Dam was not rebuilt, although Bouquet Reservoir in nearby Bouquet Canyon and Castaic Dam in the town of Castaic were subsequently built as replacements for the St. Francis Dam (in 1934 and 1973, respectively).

To this day, the exact number of victims remains unknown. The official death toll in August 1928 was 385, but the remains of victims continued to be discovered every few years until the mid-1950s. Many victims were swept out to sea when the flood reached the Pacific Ocean and were not discovered until they washed ashore, some as far south as the Mexican border. The remains of another victim were found deep underground near Newhall in 1992, and the current death toll is estimated to be more than 600 victims (excluding the itinerant farm workers camped in San Francisquito Canyon, the exact number of which will never be known).

Immediately following the disaster, Mulholland said that he "envied those who were killed" and went on to say, "Don't blame anyone else, you just fasten it on me. If there was an error in human judgment, I was the human, and I won't try to fasten it on anyone else." At the Coroner's Inquest, the leaks Tony Harnischfeger had spotted and reported to Mulholland were cited as evidence of the dam leaking the day before the break, and that both the LADWP and Mulholland were aware of them. Mulholland admitted being at the dam the day before the break, but had noticed nothing out of the ordinary, testifying that leaks in dams, especially in dams the size of the St. Francis, were common.

The Los Angeles Coroner's Inquest concluded the disaster was primarily caused by the paleomegalandslide on which the eastern abutment of the dam was built, but would have been impossible for the geologists of the 1920s to detect. Indeed, two of the world's leading geologists at the time, John C. Branner of Stanford University and Carl E. Grunsky, had found no fault with the San Francisquito rock. Therefore, the jury determined responsibility for the disaster lay with the governmental organizations which oversaw the dam's construction and the dam's designer and engineer, Mulholland, but cleared Mulholland of any charges, since neither he nor anyone else at the time could have known of the instability of the rock formations on which the dam was built. The hearings also recommended that "the construction and operation of a great dam should never be left to the sole judgment of one man, no matter how eminent."

Soon after the inquest, Mulholland retired from the LADWP and retreated into a life of self-imposed isolation. He died in 1935, at the age of 79.

In response to the St. Francis Dam disaster, California Legislature created a dam safety program in 1929 and the California Department of Water Resources was created in 1956 by Governor Goodwin Knight following severe flooding across Northern California in 1955, combining the Division of Water Resources of the Department of Public Works with the State Engineer's Office, the Water Project Authority, and the State Water Resources Board.

Analysis

Modern geologists know the type of rock found in the San Francisquito Canyon is unsuitable for supporting a dam and a reservoir, but in the 1920s, two of the world's leading geologists at the time, John C. Branner of Stanford University and Carl E. Grunsky, found no fault with the San Francisquito rock. The dam was built squarely over the San Francisquito earthquake fault, although this fault has since been inactive.

J. David Rogers, a professor of geological engineering at Missouri University of Science and Technology, published a comprehensive account of the dam's failure. The dam's failure can be attributed to three major factors: the instability of the paleomegalandslide on which the dam was built, the failure to compensate for the additional height added to the dam's design, and the design and construction being overseen by only one person.

Recently, a critique of Rogers' historical analysis of the dam's collapse was published in the journal California History (Fall 2004) by historians Norris Hundley Jr. (Professor Emeritus, UCLA) and Donald C. Jackson (Professor, Lafayette College). While accepting the validity of Rogers' geological analysis of the failure, this article makes clear how the structure built under Mulholland's direction in San Francisquito Canyon fell well short of standards for large-scale concrete gravity dams as practiced by other prominent dam engineers in the 1920s.

Mulholland Dam reinforced

Shortly after the disaster, many living below Mulholland Dam, which creates the Hollywood Reservoir, petitioned the City of Los Angeles to reinforce it. The dam, almost identical in shape and design to the St. Francis Dam, was reinforced by piling tons of earth and rock on its face.

Present-day remains

The only visible remains of the St. Francis Dam are weathered, broken chunks of gray concrete and the rusted remnants of the handrails that lined the top of the dam and the wing dike. The ruins and the scar from the paleomegalandslide can be seen from San Francisquito Canyon Road, about five miles (8 km) north of the community of Newhall in Santa Clarita.

The road sustained heavy storm damage in 2005 and when rebuilt, it was routed away from both the remains of the dam and the damaged portion of the roadway.

A mass grave for victims of the disaster is at Ivy Lawn Memorial Park, in Ventura.

In popular culture

• Robert Towne made numerous references to Mulholland, the California Water Wars, the aqueduct, and the St. Francis Dam disaster in his screenplay for the 1974 Neo-noir movie Chinatown. Mulholland is split between the characters of Noah Cross (John Huston) and the city's chief engineer Hollis Mulwray (Darrell Zwerling). In one scene, Hollis Mulwray makes a specific reference to the St. Francis Dam disaster, using the fictitious name of "Van der Lip Dam":

  In case you've forgotten, gentlemen, over five hundred lives were lost when the Van der Lip Dam gave way. Core samples have shown that beneath this bedrock is shale similar to the permeable shale in the Van der Lip disaster. It couldn't withstand that kind of pressure there. And now you propose yet another dirt-banked terminus dam with slopes of two and one half to one, one hundred twelve feet high and a twelve thousand acre water surface. Well, it won't hold. I won't build it. It's that simple. I am not making that kind of mistake twice. Thank you, gentlemen.

• Also in 1974, the movie Earthquake showed the Mulholland Dam meeting a nearly identical demise to that of the St. Francis.
• Rock musician Frank Black has made several references to the St. Francis Dam disaster in his songs, including the tracks "St. Francis Dam Disaster" and "Olé Mulholland".

See also

• Baldwin Hills Reservoir           
• Dam failure
• Malpasset Dam

• Teton Dam
• Vajont Dam

References

Notes

Further reading

• Horton, Pony R. "A Test of Integrity: The Original Story Upon Which The Docu-Drama is Based".
  • A brief journalistic article detailing the St. Francis Dam disaster. Based on Horton's 25 years of research into the story. Informational sources include Horton's interviews with Catherine Mulholland, Dr. J. David Rogers, and Robert V. Phillips, former Chief Engineer & General Manager, LADWP. [1]
• Jackson, Donald C. and Hundley, Norris. "Privilege and Responsibility: William Mulholland and the St. Francis Dam Disaster." California History (Fall 2004): 8–47.
  • This article provides extended analysis of how Mulholland's efforts in designing and building the St. Francis Dam compare with – and fall short of – other prominent concrete gravity dams built in the 1920s
• Nunis Jr., Doyce B. (Ed.). St. Francis Dam Disaster Revisited. Historical Society of Southern California. 2002. ISBN 0-914421-27-1. +
  • This collection of articles about the dam includes contributions from Catherine Mulholland, William Mulholland's granddaughter, and Dr. J. David Rogers. It is the only other book on the St. Francis Dam in print today.
• Outland, Charles F. Man-Made Disaster: The Story of St Francis Dam. A.H. Clark Company: 1977. ISBN 0-914421-28-X
  • Outland's study of the dam and the ensuing flood, first published in 1963, is the only widely published comprehensive work about the dam, the failure, and the disaster. This book is the result of good original research. An expanded edition is available from the Historical Society of Southern California.

External links

• "SAN FRANCISQUITO CANYON and the ST. FRANCIS DAM". Santa Clarita Valley Historical Society. http://www.scvhistory.com/scvhistory/stfrancis.htm. Retrieved March 29, 2003.  dozens of excellent photographs of the dam under construction, completed, its ruins, and a list of the victims.
• St. Francis Dam Disaster 30-minute television program available online.
• Remembering the St. Francis Dam Disaster, by Michele E. Buttelman, The Signal March 11, 2001.
• Google Earth image of the St. Francis Dam ruins
• St. Francis dam ruin on March 12, 1928, looking upstream with onlookers in the foreground. In "Application of the Method of Characteristics to the Dam Break Wave Problem", Journal of Hydraulic Research, 47 (1), pp. 41–49.
• St Francis Dam Flood, image gallery at USGS
• List of victims